1. Field of the Invention
The invention relates to bullet shells with a solid bullet and is suitable for firing hunting guns, preferably the guns having rifled choke barrels, within a range of up to 100 m.
2. Description of the Related Art
Rifled choke barrels were invented over 100 years ago and never gained wide acceptance due to the lack of good bullet shells suitable for the same. The patent for the rifled choke was granted to British colonel G. V. Fosberry as early as 1884. The essence of the invention consists in that the choke narrowing of a conventional smoothbore shotgun barrel is provided with rifles enabling a lead bullet to be twisted about an axis after it has passed through the rifled choke. Until 1910, the patent for the rifled choke was owned by Holland & Holland. At the time when Fosberry obtained his patent the smoothbore gun bullets had a speed not exceeding 350 m/s. However, the rifled choke is ineffective when shooting with the lead bullets whose speed exceeds 400 m/s. Long-lasting and unsuccessful experiments with various lead bullet designs for the rifled choke resulted in that a lot of gun makers tended towards the opinion that rifled chokes is a deadlock. However, the problem lies in the lack of bullet shells for such guns able to work, i.e. rotate about an axis at speeds exceeding 400 m/s and leaving the bore with no lead coating. The bullets used for rifled choke guns are usually made of a lead alloy with the following content: 85% of lead, 10% of tin and 5% of antimony. As the lead bullet passes through the rifled choke, a significant leading of the rifles occurs even after several shots whereby the grouping of shots notably deteriorates. To ensure a good grouping, it is necessary to remove the lead coating after a few shots are fired, which is a rather time and labor consuming process. It should also be noted that when a lead bullet whose speed exceeds 400 m/s enters the rifled choke its rotating bands get cut off so that no rotary motion is imparted to the bullet, i.e. the rifled choke is ineffective at speeds exceeding 400 m/s. Due to these critical factors, such a brilliant invention as the rifled choke has now been out of wide use for over 120 years in hunting wild animals within a range of up to 100 m.
Principal bullet shell designs for the hunting guns having bores with the rifled choke are known, which comprise a single-component bullet made of a lead alloy (V. P. Kostenko, “Bullets for Smooth-Bore Hunting Guns”, Moscow, The Ruchenkins Publishers, 2003, pages 139-140, FIG. 71).
As shown by the live hunting tests of many years and by indoor shooting from the smoothbore hunting guns and rifled choke guns, the main disadvantages of the prior art solutions over the claimed invention are poor internal and external ballistic characteristics thereof, i.e. increased aerodynamic resistance due to a low flight speed of the ammunition (bullet) and lack of longitudinal stability (i.e. the ammunition longitudinal axis misaligns with the direction of its flight resulting in somersaulting so that the ammunition reaches the target at an angle). All that leads to an insufficiently lasting conservation of the kinetic energy which is particularly required for killing big animals. In addition, the above solutions are characterized by an insufficient obturation as the bullet passes through the gun bore at firing because no sealing required at firing is ensured to prevent a powder gas blow-back. All that leads to insufficient stopping effect, low destructive ability and does not rule out a ricochet due to a low hitting accuracy, kill distance and penetrating performance.
The prior art closest to the claimed invention is a bullet shell for hunting guns, comprising a bullet made of a solid material with a trapezoidal groove provided on the side surface thereof, the groove delimiting a nose and a heel portions of the bullet, and a thin-wall plastic envelope enclosing the bullet, the envelope being made of two identical longitudinal halves having a cylindrical outer surface and an inner surface matching in contour with the side surface of the bullet (RU 2308672, F 42 B 30/02, Oct. 10, 2007).
This bullet shell has two significant disadvantages: 1—low longitudinal stability as the bullet passes through bushes and when shooting in a strong wind, 2—formation of huge wound hematomas in the body of an animal. However, when the bullet moves in the clear field with no obstacles such as grass, bushes, and in no wind, the grouping of shots and longitudinal stability may be referred to as excellent.
It is therefore an object of the invention to eliminate the above disadvantages. The technical effect of the invention consists in improving the external ballistics when shooting through minor obstacles (bushes, grass).